Brown dyestuffs for dyeing wool.



MAX BECKE, OF WEIDLING, NE VIENNA AND wrnnnnnf some, or MEiDLING, amt-.1

VIENNA, "AUSTRIA-HUNGARY, ASSIGNORS T FARBWERKE VORM. METSTER LUCIUS & BJEttl'NING, 0F HbGHST-ON-THE-MAIN, GERMANY, A. CORPORATION OF GM BROWN DYESTUFFS FOR DYJEING WOOL.

No Drawing.

. respectively, residing atWeidling, near Vienna, and Modling, near Vienna, respectively, Austria-Hungary, have, invented certain new and useful Improvements in Brown Dyestuffs for Dyeing" Wool, of which the following is a specification.

We have found that valuable brown dyestuffs for dyeing wool are obtained by subj ecting benzoquinone or a halogen derivative thereof to reaction with p-phenylenediaminsulfonic acid. By this reaction the monovalent atomic complex enters twice the molecule of the quinone so that compounds are produced which contain the atomic group The new dyestuffs are dark-brown powders which are readily soluble in warm water and give on wool brown dyeings of great fastness to washing and to the light, which fastness is increased by subsequently treating them with chromates or copper salts. The process for preparing these dyestuffs consists in'heating benzoquinone or a halogen derivative thereof in presence of water with p-phenylenediamin sulfonic acid, or in grinding in a dry state for a considerable time. It is advantageous when using benzoquinone to add .an oxidizing agent such as sodium bichromate, and when using chloranil an acid-binding agent.

The following example illustrates our invention, the parts being by weight: 123 parts of chloranil, 188 parts of 1-4-diaminobenzene-sulfonic acid and 272 parts of crystallized sodium acetate are intimately ground for about 24 hours. Thus a blackish-brown product is obtained which readily dissolves in water heated to 70-80 C. to a brown solution which dyes wool in an acid bath a beautiful brown tint, which tint is decidedly Specification of Le ters Patent.

A Application filed July 8, 1916. Serial No: 108,219.

Patented as regards fastness to washing and to the action of alkalis to the mixtures of yellow, red 'and blue acid-dyestuffs hitherto used for the same purposes. When the dyeing is subsequently treated with a chromate or a copper salt, the tint is rendered more intense and its fastness still improved. On precipitating the solution of the product prepared with hot water by means of a mlneral acid and salt, the dyestuif may also be obtained in a more concentrated superior, light and form by filtering the precipitated mixture when cold and drying at a low temperature. A body of similar tinctorial properties is obtalned by grinding 54 parts of benzoquinone, 18$ parts of lf-diaminobenzene-sulfonic acid, 98 parts of sodium bichromate and 95 parts of crystallized sodium carbonate.

Havingnow described our invention, what we cla m 1s 1. As new products, the dyestuffs containmg the atomic group:

being dark-brown powders, readily soluble in warm water, the solution" of which dyes wool tints of great fastness to washing and to the light, this fastness being still im- 1 proved by subsequently treating with a chromate or a copper salt.

2. As a new product, the dyestuff having the constitutional formula 

